The present invention relates to a generator for generating a product gas by means of a chemical reaction between an educt gas and a liquid, comprising a closed reaction chamber with a liquid supply, a liquid discharge, an educt gas supply, a product gas discharge, a liquid bath arranged within the reaction chamber and a substrate member arranged for rotation in the reaction chamber, the axis of rotation of this substrate member being arranged such that during a rotation of the substrate member at least part of the surface of the substrate member alternatingly dips into the liquid bath and emerges from the liquid bath wetted by the liquid.
Generators of this type are known from the literature.
The article of P. V. Avizonis, G. Hasen and K. A. Truesdell, "The Chemically Pumped Oxygen-Iodine Laser", SPIE, Vol. 1225 High-Power Gas Lasers (1990), pages 448 to 476, in particular, discloses a generator of this type for generating electronically excited oxygen gas by means of a chemical reaction between chlorine gas and basic hydrogen peroxide (in short BHP in accordance with the English designation "basic hydrogen peroxide"), whereby the electronically excited oxygen gas is used for operating a chemically pumped oxygen-iodine laser (in short COIL in accordance with the English designation "chemically pumped oxygen-iodine laser").
In this generator, the substrate member comprises a plurality of thin metal disks which are placed in a row on a shaft parallel to one another and approximately half of each disk dips into the BHP. The shaft and, with it, the metal disks are caused to rotate by means of a motor arranged outside the reaction chamber, whereby during a rotation of the metal disks the surface of the metal disks alternatingly dips into the BHP and emerges from this BHP provided with a liquid film consisting of the BHP.
Chlorine gas is blown onto the regions of the metal disks which have emerged parallel to their surface. In this respect, chlorine molecules diffuse several 100 nanometers into the BHP where the chlorine reacts with hydrogen peroxide and the lye to form electronically excited oxygen, water and a chloride.
The resulting, electronically excited oxygen diffuses out of the BHP into a gas volume of the reaction chamber and flows off into a flow channel of the chemically pumped oxygen-iodine laser where iodine vapor is injected into the electronically excited oxygen gas. As a result of collisions of electronically excited oxygen molecules with iodine molecules the latter are dissociated. The excitation energy of additional, electronically excited oxygen molecules is transferred to the resulting iodine atoms by way of collisions almost free of losses.
The excited iodine atoms and the oxygen are expanded by means of a supersonic nozzle into a resonator of the chemically pumped oxygen-iodine laser where the excited iodine atoms release their excitation energy by way of a stimulated emission of photons so that a laser beam results in a known manner.
A disadvantage of the known generator is to be seen in the fact that the substrate member is caused to rotate by a motor arranged outside the reaction chamber so that a complicated construction is required for the passage of the shaft through the wall of the closed reaction chamber. Since the interior of the reaction chamber is generally subjected to a low pressure of, for example, 50 millibars, this passage must be air-tight. In addition, no lubricating grease or oil from the seal may enter the reaction chamber where these substances could react with the BHP.
The object underlying the invention was therefore to improve a generator of the type described at the outset in such a manner that a motor arranged outside the reaction chamber for rotating the substrate member can be dispensed with and the requirement of a pressure-tight passage for a drive shaft of the substrate member through a wall of the reaction chamber is not applicable.